Leopards0Gaming

i have no idea what has happened but whenever i play tekkit classic or legends my mouse will look straight down, i've tested FTB and vanilla minecraft and those work fine, i have asked for help in the technic discord but those solutions only help it a bit, i really want to play tekkit classic but i cant due to this glitch, i cant find any answers on youtube and google so can anyone help me please, i have all my drivers updated but still no idea. EDIT:does anyone know any mods that may make this may happen.